I had heard about the Elvis/Melungeon connection but never knew what a Melungeon was. Still don't.
That special discussed the gamut: Cherokee, Black, Portugese, Native American Indian, Turkish......
I've researched Melungeons off and on for several years. They are a group of people who were already here when John Smith and gang landed in Jamestown. They were able to tell the Englishmen that they were "Porty-gee," so it's assumed that they may have Portuguese blood. They stayed one step ahead of the early frontier, serving as a buffer and as such, intermarried with Native Americans and probably escaping slaves. One theory says that Sir francis Drake dumped off a load of Turks in NC. So, it's generally believed that the ancestors of these folks are Turkish, Portuguese and more recently NA and African-American. Then, they stayed and intermarried among themselves in the hills of NC, TN, VA and KY. There's lots of theories. A very interesting group.
Near to where I live there are similar people who live in a village called Hillburn and up in the Ramapo Mountains. They are a mixture of old Dutch, black slaves, and Indians. Many of them have Dutch surnames, like Van Dunk or DeFreese. Went to school with quite a few of them.
Lately, they been trying to form a casino by claiming they are a legitimate Indian tribe - the Ramapoughs.